Current probes designed to find life on Mars cannot drill deeply enough to find living cells that may exist well below the surface, according to the study. Although these drills may yet find signs that life once existed on Mars, the researchers say, cellular life could not survive incoming radiation within several meters [yards] of the surface. This puts any living cells beyond the reach of today's best drills.
The study, to be published 30 January in the journal Geophysical Research Letters, maps cosmic radiation levels at various depths, taking into account surface conditions in various areas of Mars. The lead author, Lewis Dartnell of University College London, said: "Finding hints that life once existed--proteins, DNA fragments, or fossils--would be a major discovery in itself, but the Holy Grail for astrobiologists is finding a living cell that we can warm up, feed nutrients, and reawaken for studying."
"Finding life on Mars depends on liquid water surfacing on Mars," Dartnell added, "but the last time liquid water was widespread on Mars was billions of years ago. Even the hardiest cells we know of could not possibly survive the cosmic radiation levels near the surface of Mars for that long."
Unlike Earth, Mars is not protected by a global magnetic field or thick atmosphere, and for billions of years it has been open to radiation from space. The researchers developed a radiation dose model and quantified variations in solar and galactic radiation that penetrates the thin Martian atmosphere down to the surface and underground. They tested three surface soil scenarios and calculated particle energies and radiation doses both on the surface and at various depths underground, allowing them to estimate the survival times of any cells.
The team found that the best places to look for living cells on Mars would be within the ice at Elysium, because the frozen sea is relatively recent--it is thought to have surfaced in the last five million years--and so has been exposed to radiation for a relatively short period of time. Even here, though, any surviving cells would be out of the reach of current drills. Other ideal sites include young craters, because the recently impacted surface has been exposed to less radiation, and gullies recently discovered in the sides of craters. Those channels may have flowed with water in the last five years and brought cells to the surface from deep underground.
The study was funded by the United Kingdom's Engineering and Physical Sciences Research Council (EPSRC), the Swiss National Science Foundation, and the Swiss State Secretariat for Education and Research.
Peter Weiss | AGU
UCI and NASA document accelerated glacier melting in West Antarctica
26.10.2016 | University of California - Irvine
Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
27.10.2016 | Life Sciences
27.10.2016 | Life Sciences
27.10.2016 | Power and Electrical Engineering